Lifting apparatus



March 21, 1950 o. E. DEMPSYEY 2,501,380

LIFTING APPARATUS 1 Filed Aug. 12, 1946 6 Shts-Sheet 1 IN VENTOR. OE. D EMF S E! Q- WWW/ 3% AT NEY March 21, 1950 o. E. DEMPSEY LIFTING APPARATUS 6 Sheets-Sheet 2 Filed Aug. 12, 1946 m w w 6 a n 9 I m 425 4 M n M M. a

FmA INVENTOR.

OE. DEMPSEY Q 4 m k 'q ATTORNEY FIR;

March 21, 1950 o. E. DEMPSEY 2,501,380

LIFTING APPARATUS Filed Aug. 12, 1946 6 Sheets-Sheet 4 5O Ax INVENTOR. 0.1a. DEMDSEY A T TORNE Y March 21,1950 0. E. DEMPSEY 2,501,380

LIFTING APPARATUS Filed Aug. 12, 1946 6 Sheets-Sheet 5 ISZ IIIIIIIIIIIIIIII. P'In'll,

INVENTOR. oanampssv BY Fxs. 9 v Q W- l ATTORNEY March 21, 1950 Filed Aug. 12, 1946 0. E. DEMPSEY LIFTING APPARATUS 6 Sheets-Sheet 6 JNVENTOR.

Q EI. DEMPSEY ATTORNEY FIQJZ fluid exhausted therefrom.

Patented Mar. 21, 1950 UNITED STATES PATENT OFFICE 2,501,380 LIFTING APPARATUS Oscar E. Dempsey. Tulsa, Okla., assignor to Dempsey Pump 00., Tulsa, Okla., a corporation of Oklahoma Application August 12, 1946, Serial No. 690,006

Claims.

-to leak past a top valve to cause movement downward of a plurality of slide valves assisted by the tension of a spring in order to release mechanical latching means whereby the top valve would be moved into a position to permit direct thrust of the supply pressure fluid into a displacement chamber. The present invention utilizes a substantially lesser number of working parts, particularly omitting the mechanical latching means and tension spring to provide a more exact apparatus by the use of a positive acting valve unit directly influenced by motive pressure fluid or exhaust residue fluid to move it from open or closed position in order that the production liquid may be displaced and the residue motive In addition to the more positive functioning of the automatic valve unit, the present invention utilizes a piston valve providing a retarding or snubbing action in a manner similar to applicants co-pending application above referred to.

It is, therefore, an important object of this invention to provide a lifting unit for the displacement of fluid from a well which progressively lifts quantities of the fluid from a lower collection chamber to a reservoir disposed at a higher level, said lifting unit having a valve mechanism for controlling the discharge of supply pressure fluid into the lower chamber wherein fluid until substantially all of the production fluid from the lower chamber is displaced.

And still another object of this invention is to provide a lifting unit for displacing oil from the well by progressively lifting quantities of fluid from a lower collection chamber to a reservoir disposed at a higher level, said lifting unit having avalve mechanism controlling the input of supply pressure fluid into the lower chamber for displacing the fluid as well as the control of the 2 exhaust of the residue supply fluid after displacement of the fluid from the lower chamber, said mechanism providing for a positive bleed down to an exact minimum of the residue pressure fluid which is undisturbed by any valve leakage or sand deposits or abrasions in the mechanism.

And still another object of this invention is to provide. a lifting unit for displacing oil from the well by progressively lifting quantities of fluid from a lower collection chamber to a reservoir disposed at a higher elevation, said lifting unit having a valve mechanism controlling the'input of supply pressure fluid to provide suflicient time to increase the supply pressure fluid necessary for the displacement of the well fluid from the lower collection chamber prior to shutting off the incoming pressure fluid and thereafter allowing for an exhaust of residue pressure fluid.

And still another object of this invention is to provide a lifting unit for displacing fluid from a well which is readily adaptable to widely divergent ranges of bottom hole pressure, thereby providing a unit equally capable of operating in stripper wells having a low bottom hole pressure, or wells having a high sand pressure without dissipating the oil sand to the intrusion of water.

Another noteworthy object of this invention is to provide an automatic fluid actuated lifting unit for wells which readily adapts itself to a variable and fluctuating actuating fluid pressure wherein the operation of the unloading element is contingent upon a relationship of percentages of the actuating fluid pressure to a build up or an accumulated pressure in a storage chamber.

And an additional object of this invention is to provide an automatic fluid actuated lifting unit for wells which is adapted for a continued operation irrespective of a complete or partial replacement of the production fluid from the production strata, said unit providing a rate of production fluid displacement exceeding the maximum rate of production fluid entering the well bore without seriously affecting the working parts so that the wellmay be continuously produced at a bottom hole pressure substantially suflicient to maintain a fluid level in proximity of the unit.

And an additional object of this invention isthe economic use of small volumes of gas in cubic feet for progressively lifting small amounts of fluid into a reservoir to be intermittently slugged in predetermined quantities, thereby eliminating the use of large volumes of gas to slug small amounts of entrapped oil all the way through the tubing string.

Other objects and advantages of the invention will be evident from the following detailed description read in conjunction with the accompanying drawings which illustrate my invention.

In the drawings:

Figure 1 is a sectional elevational view of the well bore showing a portion of the lifting unit in elevation disposed therein.

Figure 2 is a similar view showing the remaining portion of the lifting unit. 9

Figures 3 and 4 are fragmentary sectional elevational views of the lifting unit per s showing one operating position of the valves.

Figures 5 and 6 are fragmentary sectional elevational views in schematic arrangement showing another position of the valves.

Figures 7 and 8 are views similar to Figures 5 and 6 showing the valve mechanism in still another position.

Figures 9 and 10 are similar views and showing the valve mechanism in still another position of operation.

Figures 11 and 12 are views similar to Figures 9 and 13 showing the valve mechanism in another position of operation.

Figure 13 is a sectional view taken on lines of Figure 3. I

Figure 14 is a sectional view taken on lines |2|2 of Figure 1.

Figure 15 is a sectional view taken on line |3 |3 of Figure 1.

Referring to the drawings in detail and more particularly Figures 1 and 2, reference character 2 represents the well casing extending from the surface of the well to the producing strata thereof. A string of well tubing 3 is disposed in spaced relation within the casing 2. A lifting unit 4 is suspended on the tubing 3 on a string of macaroni tubing 5 of reduced diameter. The lowermost section of the tubing 3 in proximity of the production strata is specially formed to include inwardly projecting shoulders 6 for supporting a flange portion 1 of the unit 4 when inserted in the tubing 3. It will be apparent that the shoulders 6 also support the tubing 5 extending to the surface of the well. The lower end of the unit 4 is provided with packing rings 8 for anchoring the unit in a reduced nipple 9 of the tubing 3. A gas anchor ill having a plurality of perforations or apertures II is secured to the tubing 3 in spaced relation thereto at a point below the casing 2.

Referring to Figures 3 and 4 the lifting unit 4 comprises a cylindrical housing l2 adapted at its upper end to receive the valve unit I3 and a manifold at its lower end. Housing l2 has a bore I5 of varying diameters in which is disposed the pressure fluid is constantly maintained in the tubing 6, in direct communication with a passageway 26 provided in the unit 4. The input duct 26 is composed of aligned passageways through members 21, 29, II and I2, and communicates with bore I! in which is disposed the upper portion of main valve unit l4. The main valve unit |4 comprises an outer cylindrical sleeve 29, having lower tapered valve member 3| secured thereto. The outer periphery of the sleeve 29 is provided with conventional sealing or packing members 32 effectively sealing of! the upper portion of bore l5 from direct communication with passageway 26. This upper portion of bore l-5 above the valve sleeve 29 Provides a chamber 33. A cylindrically-shaped pilot valve 34 having a bore 35 therein is slidable within the sleeve 29. The sleeve 29 is provided with a plurality of ciroumferentially-spaced apertures 36 in communication with the input passageway 26. The lower portion of main valve I4 is adapted to operate in a bore 31 of the cylinder 23 and engage the tapered seat 38 of the plate 22 as will hereinafter be referred to. The bore 35 of pilot valve 34 communicates with an aperture 39 therein and a bore 49 of valve 3|, and bore 4| of cylinder 24 and into cavity 42 of member 24 in which is located the pilot valve tripping dev'g e adapted to cooperate with main valve l4,

With the valve |4 shown in its open or input position (Fig. 3) the supply pressure fluid discharges from passageway 26 into bore |5 and hence through the apertures 36 into the chamber 33 and through the apertured plug 43 secured to the pilot valve 34"to discharge into the chamber 35 below the plug. A spherically-shaped valve 41 is positioned within the chamber 35 and cooperates with the aperture 39 provided in the pilot valve. The aperture 39 has tapered portions 46 acting as a seat for the sphericallyshaped ball valve 41. The valve sleeve 29 is disposed in spaced relation to the inner periphery of the bore l5 to provide a lower chamber 48, in direct communication with supply pressure fluid which simultaneously flows through port 49 in plate 22 and into bore 31 and passageway 59 in communication with the chamber 42 provided by the cylindrical member 24 arranged in spaced relation to housing 2. The lowermost portion of cavity 42 is of reduced diameter provided by a recess in the upper end of manifold 5| from which a passageway 52 extends downwardly therethrough. The lower end of manifold 5| is secured to tubular member 53 and is provided with a counterbored recess 54 for receiving the cylindrical member 55 disposed in spaced relation to the central bore 56 of manifold 5|. The lower ends of members 53 and 55 are secured by tight-fitting collar 51 having an aperture 58. Passageway 52 communicates with the annulus 59 formed by members 53 and 55 and supply pressure fluid flowing therethrough has an outlet port 60 provided in collar 51. Thus the lower portion of chamber 6| provided by cylinder 55 is in direct communication with input passageways 50 and 52 as well as chamber 42.

The chamber 6| contains the piston unit 62 which is similar in structure to that disclosed in applicant's co-pending application Serial No. 645,305 heretofore mentioned. A perforated tube 63 extends downwardly from collar 51. A cage member 64 having a ball valve 65 is provided at the lower end of tube 63. The packing rings 6 surround the outer periphery of the cage 64 and are adapted to anchor the lowermost end of the unit 4 in the reduced nipple 9, as shown in Figure 2. The chamber 6| housing the piston unit 62 which comprises a cylindrical piston 61 having a flange 68 provided on the outer periphery thereof. A plurality of rings and cups l0 bear against the inner periphery of the cylinder 55, with the cylinder 61 arranged in spaced relation thereto. The upper end of. the cylinder 61 is provided with apertures 59 for a purpose as will be hereinafter set forth. The lower portion 1| of the cylinder 6! extends through the aperture 58 in the collar 51, so that a portion of the cylinder 61 is substantially disposed within the conflnes of the tube 63. A valve cage I2 is secured to the lower end of cylinder 61 and contains a ball valve 13 for a purpose as will be hereinafter set forth. The tube 63 is provided with a plurality of vertically-spaced apertures 14 (Figure 2) providing communication between the interior I5 and a chamber 16 formed between the cylinder 63 and,tubing 3. It will be apparent that the apertures 14 will equalize fluid pressures and levels therebetween. Packing rings 18 are disposed on the outer periphery of the manifold 5| and contact the projection 6 of the tubing 3, as shown in Figure 1.

Operation 26 from a surface compressor or'like equipment (not shown) and with the valve in open position,

as shown by Figures 3 to 6 is discharged through passageways 56 and 52 into the chamber 6| beneath the piston flange 68 thereby causing movement of the piston unit 62 vertically upward. Movement of the piston unit 62 partially moves the upper cylinder 61 into the longitudinal bore 56 provided in member 5|. The bore 56 communicates with an annulus or reservoir 86 provided between the tubing 3 and 5 (Figure 1) through an outlet port 8| provided in member 5|. However, upward vertical movement of the piston unit 62 is limited or retarded due to previously displaced well liquid or fluid that is normally present in chamber 6| above the flange 68.

Movement of the piston unit 62 vertically upward is due to a pressure differential between the upper part of chamber 6| above the flange 68 and the lower portion thereof, below the flange 68. The upward movement of the piston unit 62 is retarded or arrested because the piston unit 62 moves upwardly against the volume of previously displaced well liquid or fluid that is present in the chamber 6| and bore 56 above the flange. As the piston unit moves upward in chamber 6| the snubbing action provides an element of time which enables the motive pressure fluid flowing from the chamber 6| below the flange and through the port 58 and into the displacement chambers 16 to build up the pressure in the displacement chamber sufliciently to overcome the static pressure of the liquid above the ball valve 13 thereby causing displacement or movement of the production liquid from the chamber 16.

As supply pressure fluid discharges through port 58 into the displacement chamber it will build up or increase the pressure therein suiflcient to cause displacement of the production liquid in the chamber 16 and discharge through the ball valve 18, simultaneously causing movement of the liquid in the chamber 82 between the ball valve 13 and the outlet port 8|. The arresting of the piston unit 62 will be maintained during the displacement of liquid from the chamber I6, because the volume of liquid flow through outlet port 8| is less than the volume of supply fluid capable of flowing through the port 58 due to the characteristic differences of liquid versus gas flow. Therefore the volume of supply pressure fluid through port 58 will maintain a pres sure condition in displacement chamber 16, bores 56 and 82 greater than the static pressure condition upstream from outlet port 8|, as long as liquid commands port 8|'.\ This pressure in 16, 56, and 82 will closely approximate pressure of a gas in lower portion of 6| and thus obviously in upper part of 6|. Continued displacement of the liquid from chamber 16 and through ball valve I3 and outlet port 8| moves substantially all of the liquid through the outlet port 8| thus uncovering port 84 to cause discharge of the motive pressure fluid through the ball valve 13, bore 56- ,into bore 56, by the motive pressure fluid acting against the underface of flange 68 to move the piston unit 62 vertically upward to the top of the chamber 6| (Figure 8) and fluid through the port 8| .completing the movement of piston unit 62.

It will be apparent that the retarded position of piston 62 will remain substantially stationary during the displacement of production fluid entrapped in chamber 16 however the snubbing action of the piston unit 62 is only necessary for the time required for the volume of supply pressure fluid flowing through port 58 to be increased, and provide a greater pressure in chamber 16 than the static pressure of liquid commanding port 8| irrespective of the static pressure condition at port 8| under any condition. From the foregoing, it will be obvious that time interval will be variable depending upon the variable pressure conditions that may be present or may command port 8|.

The completed upward travel of the piston unit 62 (Figure 8) causes the cage 85 of cylinder 6'! to contact a valve trip rod 86 extending from chamber 42 through an aperture 81 in member 5| and into the bore 56. An extension 88 of reduced diameter is secured to the lower end of trip rod 86 and extends through the apertured cage 85 into the chamber 82 of thecylinder 61. An enlarged projection 89 is provided at the end of extension 88 in order to maintain it within the cylinder 61. The contact of the a top part 85 of cylinder 61 with the trip rod 86 ward into contact with the apertured plug 43. This will provide vertical upward movement of the pilot valve 34 in the sleeve 29 past the plurality of apertures 36, thereby closing off chamber 33 from the input of pressure fluid in passageway 26. With the valve 41 in unseated condition as shown in Figures and 7 the volume of fluid pressure in chamber 33 discharges through apertures 93 in plug 43 through aperture 39, bore and a small leak-port 95 in cylinder 24 providing communication, between bore 40 and an exhaust passageway. The exhaust passageway extends from communication with port I8 by a drilled aperture 91 in inwardly projecting shoulder 98 of cylinder I2, and aligned apertures 99, I00 and "II in members 22, 23 and 24, respectively. The tubing 31 (Figure 1) is provided with a plurality of circumferentially spaced apertures I03 providing communication between port I02 in manifold 5| and an annulus I04 provided between tubing 3 and easing 2.

Movement of the rod 86 upwardly contacts and moves the flange plate 9| upwardly into an effective contact with faced end I05 of bore 42. The. tapered valve member 3| is provided with a. faced end I06 contacting a portion of the upper end of cylinder 24 exposed to bore 31 of cylinder 23. Therefore, with the valve positions as shown in Figure 5, the leak port 95 is in direct communication with the volume of supply pressure fluid containedin bore 4| and 40, aperture 39 and chamber 33. The reduced pressure in chamber 33 permits the thrust of input supply pressure constantly maintained in chamber 43 to move the main valve= unit I4 upwardly to a position which brings the tapered shoulders I01 of valve 3| into seating position with tapered portion 38 of plate 22 as shown in Figures 3 and '1. This movement closes ofl passageway from communication with passageway 26 and the flow of supply pressure fluid therefrom, and further opens passageway 50 to a modulated or restricted communication with the lower or exhaust pressure area now present in bore 31 of cylinder 23 directly communicating with the full area of discharge passageway 96. The upward movement of valve unit I4 and particularly of sleeve 29 alters the relative position of the pilot valve 34 with the apertures 36 as will be hereinafter referred to. An apertured thimble I09 secured to cross-over plate I6 cooperates with the movement of sleeve 29 to regulate the positioning of valve 34 and may be so arranged as to substantially move the apertured plug 43 out of contact with valve 41. It will be understood that the relationship of pressures is commensurate with the areas of the various valves, pistons and bores and the ratio between them is a matter of choice depending upon a particular unit.

with the valve unit 4 in the position, as shown in Figure 7, the residue pressure fluid present in the displacement chamber 16 and chamber 6| below the flange 68, passageway 59, chamber 42 and passageway 50 is allowed to exhaust around the reduced outer periphery I I0 of the lower body portion of valve member 3|, and into the exhaust passageway 96. The exhaust of supply pressure fluid from the displacement chamber and input passageways, relieves pressure against valve 13 andpermits the oil or production fluid that has been displaced to the annulus 80 to move the piston unit 62 vertically downward to a position as shown in Figure 10. Downward movement of piston unit 62 also moves rod 66 and upper flange ll downward due to cage 85 of cylinder 61 contacting rod flange 39.

The flange 9| will remain seated against the face I05 of cylinder 24 until the pressure of the residue supply fluid present in chamber 42 bleeds off sufliciently to no longer hold the weight of flange 9|, rod 92 and valve 41 firmly against the face I05. It is understood that the low pressure area formed above plate 9|, when firmly seated against face I05 permits the higher pressure in chamber 42 to maintain the combined weight of the flange, rod and valve thereagainst. The escaping exhaust pressure flowing from cavity 42 and passageway 50 into the bore 31 must pass by the reduced portion 0 of valve 3|, and through a port III communicating with exhaust passageway 96. The bleeding down of residue pressure fluid provides a pressure in chamber 31 substantially equal to the bottom hole pressure in annulus I04. From the foregoing it will be apparent that the flange 9| is maintained against its seat I05 until substantially all residue pressure fluid is exhausted thereby permitting flow of production fluid through valve under influence of the sand pressure.

In this condition as shown in Figure 9, supply pressure fluid present at apertures 36 is allowed to leak around the outer periphery of the pilot valve 34 and a reduced portion thereof II2 into the chamber 33. The leakage of motive pressure fluid is permitted by the loose flt of the pilot valve 34 with its bore, the inner periphery N3 of the sleeve 29. Leakage of supply pressure fluid into the chamber 33 builds up a pressure condition therein to force the pilot valve 34 downward and thereby open apertures 36, whereb chamber 33 is subject to the full pressure of the supply fluid to cause vertical downward movement of the valve unit I4, as clearly shown in Figure 3, thereby moving valv section 3| downward to open port 49 allowing discharge of supply pressure fluid into the passageway 50' and 52 and port 58, so that the operation against the piston unit 62 and displacement chamber 16 is repeated.

The foregoing has been concerned mainly with the action of the main valve unit I4 and piston unit 62 for the displacement of liquid entrapped in the chamber 16 to a reservoir or storage chamber located at a higher elevation. It will be apparent from the description, supra, that the operation of the main valve I4 re-occurs without regard to or the presence of oil existing in the displacement chambers 16. During the cycles of operation in which the main valve operates without any oil, or suflicient oil in the displacement chamber to warrant the presence of suflicient oil above the valve 13 in chamber 16, it will be obvious that the piston unit 62 is capable of moving through its complete cycle uninterrupted by the flow of entrapped oil flowing in chambers 82 and 56. This condition will obviously cause a more expeditious function of the flange 9| and its valve 41 to close off the input ports 36 through an upward movement of the pilot valve 34.

The oil displaced to the reservoir 80 builds up a hydrostatic head of pressure therein acting against the upper differential valve unit I3 previously referred to.

eferring to Figures 1 and 3 the valve unit l3 comprises the upper housing member 2| interconnected between th housing I2 and the upper plug 21 in turn connected with the macaro tubing 5, as shown in Figure 1. The cylindrical member 2| is provided with a valve manifold 28 to having abore H5 communicating with aligned a bores H6 and III in cylinder 2| to provide a housing for the valve unit I3. The unit I3 comprises an upper piston II8 secured to a shaft H9 extending downwardly therefrom. The outer periphery of the piston H8 is provided with a plurality of packing cups I2II adapted to contact the inner periphery of the bore II for a purpose as will be hereinafter described. The lower portion of shaft H9 is of increased diameter as at I2I providing tapered portions I22 adapted to cooperate with a tapered aperture I23.provided in the manifold 28. The valve portion I2I is provided with a recessor socket I24 for receiving a ball projection I25 of a sliding valve I26 extending downward therefrom into the bores I I6 and Ill. The plug 21 is formed with a passageway I2I providing communication with the reservoir or annulus 80 and the bore II5 above they piston H8. The member 2| is similarly formed with a port I30 providing communication with the reservoir 80 and the bore II6 for a purpose as will be hereinafter set forth. The constantly maintained motive pressure fluid is directed from the macaroni tubing 5 downward into a passageway I3I in plug 21 into communication with an annulus I 32 which in turn communicates with a passageway I33 provided in the manifold 28 to direct supply pressure fluid from the tubing 5 into the bore I I5 beneath the piston II8. With the piston H8 in closed position, as shown by Figures 3 and '7, it will be understood that the piston will remain as such by the presence of supply pressure fluid acting against the lower face thereof, and also influenced by the reservoir pressure in passageway I30 leaking past the loose fit of valve I2I in the bore H8, until the hydrostatic head of displaced production liquid in reservoir 80 acting against the top of piston H8 through passageway I2! is suflicient to overcome the upward thrust thereagainst. The bore H1 is in communication with the exhaust passageway 96 as clearly shown in Figure 3 and as a consequence there may be a negligent pressur existing against the underface of valve I26 from the exhaust passageway 96. It will be apparent that if there is any exhaust or casing pressure in passageway 96, the reservoir pressure acting against the top of piston -I I8 must be sufiicient to overcome this pressure as well as the effective area of supply pressure fluid in existence in bore H5 below the piston H8.

The ratio of the area between th bore II5, he effective seating area of the tapered valve l2l at its tapered seat I23, and the perfect seal :reated by the lower piston valve I26 in its bore establishes the percentage f pressur necessary in the reservoir 80 to overcome the effective upward thrust of supply pressure fluid existing in chamber II5 below piston H8, and the exhaust pressure acting against the lower valve I2I from the exhaust passageway I36, to move the piston H8 downward along with downward movement of the valves I2I and I26 thereby opening port I30 to the direct discharge of supply pressure fluid from bore H5 and passageway I33 in order to slug the liquid standing in the reservoir 80 to the top of the Well.

In order to obtain the percentage of pressure to'move piston II8 downward (Figure 5) in relation to the supply pressure fluid, it will be apparcut that the area of the piston I I8 minus the effective area of the tapered portions I22 of valve I2I multiplied by the pressure maintained in chamber I I5 will produce the sum of the upward thrust acting against the lower face of piston I l8.

The downward thrust is obtained by the area of piston "8- plus the area of valve I26, minus the effective area of the tapered portion I22 multiplied by the pressure in the reservoir. This is because the reservoir pressure acts upwardly againstvalve I2I, and downwardly against valve I26. Therefore in Order to determine the pressure required to move the piston H8 and open the valve I2I away from its tapered sea-t I22 will be the sum of the areas and pressures obtained from the downward thrust relative to the sum of the areas and pressures obtained by the upward thrust.

It willbe apparent that once the flow starts in the annulus 80 that the pressure of the input fluid will also be directed through the passageway t2! and assist in maintaining the piston H8 in downward position (Figure 11) until substantially all of the oil is slugged from the annulus to the top of the well. As soon as the oil is displaced from the annulus 80, a diminished pressured condition exists in the annulus due to the exhausting and expansion of the input fluid therein. This permits the greater pressure in chamber I I5 acting against the bottom of the piston H6 and move it to closed position as shown in Figure 3.

It will be apparent that the areas of the various valves and their bores are variable and the relationship therebetween is dependent upon a particular unit and the environment or characteristics of the well with which it is utilized. Both the opening and closing pressure of the valve unit I3 may be varied within a selected range of operating efficiency.

From Figure 1 an apertured screen I 40 is shown disposed in the macaroni tubing 5 and is employed to keep the incoming motive pressure fluid discharging through the valve unit I4 substantially free from pipe scale and other debris, while the motive pressure fluid entering and discharging to the intermittent valve unit I3 may be taken from a sump I4I surrounding the screen I40.

From the foregoing, it will be apparent that the invention contemplates the intermittent lifting of small quantities of oil from a lower filling chamber to a higher reservoir, and functions in such manner to prevent any supply pressure fluid utilized for displacing theoil from counteracting the sand pressure of the well, so that there is always a constant emission of fluid from the production strata except for the momentary period during the displacement operation. Furthermore, the lifting unit comprises an automatic valve mechanism for controlling the supply pressure fluid into the displacement chamber, and assures that substantially all of the production fluid is displaced from the filling chamber prior to shutting ofi the supply pressure fluid. Furthermore the present invention provides a definite means of determining exactly how much residue pressure is present in the filling chamber before the valve reopens to the discharge of motive pressure fluid. This is accomplished by having a definite amount of weight imposed against an orifice when the pressure down is no longer suflicient to hold the weight of-the flange 9| holding the valve 41 away from its seat. The flange 9| and valve 4'! are allowed to drop under gravity of their own weight and are not hindered by any particles of sand that may be present in the residue fluid, or any mechanical hindrances such as springs or the like. The present invention is capable of being utilized in wells having a high sand pressure maintaining a high fluid level in the well bore, and is also very adaptable to oil wells where only a minimum of fluid is present at the bottom of the bore in what are commonly known as "stripper wells providing a low fluid level. In the latter adaptation the only production pressure necessary would be an amount necessary to move the ball valve 65 off its seat allowing the flow of well liquid into the displacement chambers against whatever small amount of residue pressure may be present in the displacement chambers.

Changes may be made in the combination and arrangement of parts as heretofore set forth in the specification and shown in the drawings, it being understood that any modification in the precise embodiment of the invention may be made within the scope of the following claims without departing from the spirit of the invention.

In the claims:

1. In an apparatus for lifting fluid from a well comprising an automatic valve unit communicating with an inlet passageway having constantly maintained motive pressure fluid therein, and a filling chamber for well fluid emitting from the production strata, a reservoir communicating with the valve unit and the filling chamber, said valve unit comprising a valve mechanism movable by motive pressure fluid to one position for directing motive pressure fluid to the filling chamber, and movable to another position preventing discharge of motive pressure fluid .to the filling chamber and simultaneously permitting an exhaust of residue motive fluid therefrom, and means in the valve mechanism directly responsive to the motive pressure fluid for maintaining the valve mechanism in the first mentioned position, a piston unit movable in response to motive pressure fluid and operably connected with the above mentioned means to cause a movement thereof permitting the valve mechanism to be moved to the position allowing exhaust of residue motive fluid from the filling chamber, and means independent of the valve mechanism and responsive to'the hydrostatic head of well fluid in the reservoir for introducing motive pressure fluid thereto for slugging the well fluid to the top of the well.

2. In an apparatus for lifting fluid in a well comprising an automatic valve mechan sm communicating with an inlet passageway having constantly maintained motive pressure fluid therein, a filling chamber for well fluid emitting from the production strata, a piston movable in response to motive pressure fluid into operable connection with the valve mechanism, said piston moving against previously displaced well fluid to provide a snubbing action for the piston until substantially all of the production fluid is displaced from the filling chamber, means in the valve mechanism responsive to the movement of the piston permitting movement of the valve mechanism to a position for exhausting residue motive fluid from the filling chamber, said means maintained in said position by the pressure of the residue motive fluid after displacement of the well fluid until there is substantially complete exhaust or the residue fluid from the apparatus.

3. In an apparatus for lifting fluid in a well comprising an automatic valve mechanism communicating with an inlet passageway having constantly maintained motive pressure fluid therein, a filling chamber for the well fluid emitting from the production strata, a piston movable in response to motive pressure fluid into operable connection with the valve mechanism, said pr'ston moving against the previously displaced well fluid providing a snubbing action for the piston until substantially all of the production fluid is displaced from the filling chamber, a pilot valve in the valve mechanism controlling the movement thereof, a valve controlling the movement of the pilot valve, said last mentioned valve responsive to the movement of the piston to cause movement of the pilot valve to a position permitting exhaust of residue motive fluid from the filling chamber, said valve maintained in said last mentioned position by the pressure of the residue motive fluid after displacement of the well fluid until there is a substantially complete exhaust of the residue fluid from the filling chamber whereby said valve is permitted to move to its original position by gravity.

4. In an apparatus for lifting fluid from a well comprising an automatic valve mechanism communicating with an inlet passageway having constantly maintained motive pressure fluid therein, a filling chamber for the well fluid emitting from the production strata, a piston movable in response to motive pressure fluid into operable conneetion with the valve mechanism, said piston moving against the previously displaced well fluid providing a snubbing action for the piston until substantially all of the production fluid is dis placed from the filling chamber, a pilot valve in the valve mechanism controlling the movement thereof, a valve controlling the movement of the pilot valve, said last mentioned valve responsive to the movement of the piston to cause movement of the pilot valve to a position permitting exhaust of residue motive fluid from the filling chamber, said valve maintained in said last mentioned position by the pressure of the residue motive fluid after displacement of the well fluid until there is a substantially complete exhaust of the residue fluid from the filling chamber whereby said valve is permitted to move to its original position by gravity, and an independent valve unit comprising a series of vertically spaced valves in communication and responsive to the hydrostatic head of well fluid in the reservoir for introducing motive pressure fluid into the reservoir for slugging the well fluid to the top of the well.

5. In an apparatus for lifting fluid in a well including a filling chambena valve unit for controlling the introduction for constantly maintained rrotive pressure fluid into the filling chamber for displacing oil emitting thereto from the production strata, a reservoir for receiving the displaced fluid, said valve unit comprising an elongated valve movable in one position to permit discharge of motive pressure fluid to the filling chamber, and movable in another position to prevent discharge of motive pressure fluid to the chamber and simultaneously permitting exhaust of residue motive fluid from the chamber, a pilot valve slidably disposed in the elongated valve for controlling the flow of motive pressure fluid causing movement of said elongated valve to said first mentioned position, a polygonal valve disposed in the pilot valve for controlling the movement thereof, a lower piston unit operably connected with the polygonal valve and responsive to motive pressure fluid to cause an unseating of said polygonal valve and permitting an exhaust of the motive pressure fluid from one side of said elongated valve to permit a movement of said elongated valve into position for exhausting residue motive fluid from the filling chamber, said polygonal valve adapted to remain in said unseating position by the pressure of the residue fluid until a substantially 13 complete exhaust of the residue motive fluid whereby the polygonal valve is moved by gravity to a seating position.

6. In an apparatus for lifting fluid in a well including a filling chamber, a valve unit for controlling the introduction for constantly maintained motive pressure fluid into the filling chamber for displacing oil emitting thereto from the production strata, a reservoir for receiving the displaced fluid, said valve unit comprising an elongated valve movable in one position to permit discharge of motive pressure fluid to the filling chamber, and movable in another position to prevent discharge of motive pressure fluid to the chamber and simultaneously per-' mitting exhaust of residue motive fluid from the chamber, a pilot valve slidably disposed in the elongated valve for controlling the flow of motive pressure fluid causing movement of the elongated valve to said first mentioned position, an aperture in the pilot valve in communication with the exhaust passageway, a polygonal valve disposed in the pilot valve and movable on and away from the aperture to control movement of the pilot valve, a piston unit operably connected with the polygonal valve and responsive to motive pressure fluid to cause an unseating of the polygonal valve from the aperture and permitting an exhaust of the motive pressure fluid from one side of said elongated valve to permit movement of said valve into a position for exhausting of residue motive fluid from the filling chamber, said polygonal valve adapted to remain away from said aperture until a substantially complete exhaust of the residue motive fluid from the filling chamber to permit the valve to move by gravity to a seating position against the aperture.

7. In an apparatus for lifting fluid from a anism to the last mentioned position until sub-. 'stantially all the well fluid is displaced from the filling chamber, and means in the valve mechanism maintained in said last mentioned position by the pressure of the residue motive fluid until a substantially complete exhaust of the residue motive fluid from the apparatus, and means independent of the valve mechanism and responsive to the hydrostatic head of well fluid in the reservoir for introducing motive pressure fluid thereto to slug the well fluid to the top of the well.

8. In an apparatus for lifting fluid from a well having an eduction tubing and a well casing, said apparatus including a reservoir communicating displacing well fluid therefrom, said mechanism operable in another position to bleed oif residue motive pressure fluid after displacement of well fluid from the filling chamber, and an independent intermitting valve mechanism comprising an elongated valve having upper and lower seating members in communication with the motive pressure fluid, a piston valve extending from the lower seating member in vertical spaced relation thereto, said elongated valve and piston valve responsive to the hydrostatic head of fluid in the reservoir to move said lower seating member to a position permitting discharge of motive pressure fluid to the reservoir for slugging the well fluid to the top of the well.

9. In an apparatus for lifting fluid from a well having an eduction tubing and a well casing including a reservoir communicating with the eduction. tubing, a filling chamber communicating with the well casing and the reservoir, an automatic valve mechanism operable in one position to direct constantly maintained motive pressure fluid into the filling chamber for displacing well fluid therefrom, said mechanism operable in another position to bleed oif residue motive pressure fluid after displacement of well fluid from the filling chamber, a tripping mechanism operably connected with the valve mechanism for controlling the positioning thereof, said tripping mechanism maintained in one position by the residue pressure fluid during the exhausting thereof to maintain the valve mechanism in said last mentioned position, said tripping mechanism adapted to be moved by gravity to another position with a substantial exhaust of the residue pressure fluid whereby said valve mechanism is permitted to move to the said first mentioned position.

10. In an apparatus for lifting fluid from a well having an eduction tubing and a well casing including a reservoir communicating with the eduction tubing, a filling chamber communicating with the well casing and the reservoir, an automatic valve mechanism operable in one position to direct constantly maintained motive pressure fluid into the filling chamber for displacing well fluid therefrom, said mechanism operable in another position to bleed oi! residue motive pressure fluid after displacement of well fluid from the filling chamber, means operably connected with the valve mechanism for controlling the positioning thereof, said means maintained in one position by the residue pressure fluid during the exhausting thereof to maintain the valve mechanism in said last mentioned position, said means adapted to be moved by gravity to another position with a substantial exhaust of the residue pressure fluid whereby said valve mechanism is permitted to move to the said 6 first mentioned position.

with the eduction tubing, a filling chamber communicating with the well casing and the reservoir, an automatic valve mechanism operable in one position to direct constantly maintained motive pressure fluid into the filling chamber for OSCAR nynmrrsnr.

REFERENCES crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,896,162 Dempsey Mar. 5, 1946 i 2,469,225 Dempsey May 3, 1949 

